Patent Application
20080045108
The present invention relates to a resin composition and a molded product comprising the same. The molded product is characterized in that the fluorine-containing polymer is segregated on a surface of the molded product. The molded product can be used as home household articles, stationeries, interior materials, sanitary supplies, medical supplies and the like.
Hitherto, known are technologies of subjecting a surface of a molded article to a fluorine treatment to impart the water- and oil-repellency to the surface. A method of conducting the fluorine treatment after the molding, however, has the problem that the durability of water- and oil-repellency is weak so that the repeated use makes the water- and oil-repellency to be deteriorated. In order to solve this problem, the studies have been made that a fluorine-containing compound is added to a resin and then melt-kneaded before the molding of resin so that a fluorine component is segregated on a surface after the molding, to impart the water- and oil-repellency.
For example, Japanese Patent No. 2631911 discloses that a composition, which prepared by melt-kneading an oily or gum perfluorinated polyether or perfluorinated polypropylene oxide with a thermoplastic resin, can form a molded article wherein a fluorine content is different between an internal part and a surface of the molded article to segregate a larger amount of fluorine on the surface
The fluorine-containing additive, however, has relatively poor compatibility with the thermoplastic resin so that the kneading at high efficiency and high shear in an extruder is necessary. Japanese Patent No. 2505536 discloses that an ester of a monohydric or dihydric alcohol with a compound having a perfluoroalkyl group and one carboxyl group is melt-kneaded with a plastic and then molded to impart the water- and oil-repellency to a molded article. The amount of the fluorine-containing additive, however, is large to be about 5% by weight so that the cost of product is disadvantageous.
Japanese Patent No. 1574020 discloses that a polyfluoroalkyl ester compound limited to a compound melting at a molding temperature is kneaded with a rubber and subjected to a heat press first vulcanization at 180° C. for 10 minutes and an oven second vulcanization at 150° C. for 15 hours, consequently the polyfluoroalky.l ester compound is bled on the surface to form a non-tacky surface, whereby imparting the mold releasability and the water- and oil-repellency. Japanese Patent No. 2685904 discloses that a perfluoroalkyl group-containing ester is formulated with a thermoplastic resin in the amount of 0.1 to 5% by weight based on the thermoplastic resin, melt-kneaded, molded and then heat-treated at 70 to 130° C. to exhibit the repellency to a solution containing a surfactant such as liquid cleaning agent. Intended alcohol repellency, however, cannot be obtained when the molded article produced by this method is evaluated.
U.S. Pat. No. 6,380,289 discloses a thermoplastic composition prepared by incorporating a semi-crystalline first thermoplastic polymer with a surface modifier containing a fluorine-containing aliphatic group and a second thermoplastic polymer. The fluorine-containing aliphatic group in the surface modifier has 8 carbon atoms, as shown in Examples of said US patent.
Described below are the environmental problems raised by perfluorooctanoic acid (PFOA). The results of the latest researches [a report of the Environmental Protection Agency. (EPA), “PRELIMINARY RISK ASSESSMENT OF THE DEVELOPMENTAL TOXICITY ASSOCIATED WITH EXPOSURE TO PERFLUOROOCTANOIC ACID AND ITS SALTS” (http://www.epa.gov/opptintr/pfoa/pfoara.pdf)] have taught that PFOA (perfluorooctanoic acid), one of long chain fluoroalkyl compounds, is proved to have a danger to burden the environment. Under such a situation, EPA announced on Apr. 14, 2003 that the scientific investigation on PFOA should be more intensively executed.
On the other hand, the Federal Register (FR Vol. 68, No. 73/Apr. 16, 2003 [FRL-7303-8], http://www.epa.gov/opptintr/pfoa/pfoafr.pdf), EPA Environmental News FOR RELEASE: MONDAY Apr. 14, 2003 EPA INTENSIFIES SCIENTIFIC INVESTIGATION OF A CHEMICAL PROCESSING AID (http://www.epa.gov/opptintr/pfoa/pfoaprs.pdf) and EPA OPPT FACT SHEET Apr. 14, 2003 (http://www.epa.gov/opptintr/pfoa/pfoafacts.pdf) have published that telomers have a possibility to produce PFOA when decomposed or metabolized (herein, the telomer means a long chain fluoroalkyl group), and also that telomers have been widely used in foam fire extinguishers, care products, washing materials, carpets, textiles, paper, leather, etc., in order to impart water and oil repellency and soil resistance to them.
Problems to be Solved by the Invention
In order to maintain the repellency, it is necessary to segregate a fluorine-containing compound on a surface of a molded product by melt-kneading and molding a polymer and the fluorine-containing compound. Even if the molded articles, however, are produced according to conventional procedures, the limited conditions must be used for the reason of use of the fluorine-containing compound having poor compatibility with the thermoplastic resin, in order that the fluorine-containing compound is easily segregated. In addition, even if the usual conditions can be used for the kneading, there are unpreferably problems in terms of cost and process, such as the problem that a large addition amount of the fluorine-containing compound should be used.
Means for Solving the Problems
The present inventor intensively studied to solve these problems, discovered that a fluorine-containing compound is effectively segregated on a surface by melt-kneading and molding a thermoplastic resin with a specified fluorine-containing polymer to give a molded article, and therefore completed the present invention.
The present invention provides a resin composition comprising:
The present invention relates also to a molded article molded from the resin composition. The shape of the molded article includes a fiber, a film and a tube.
According to the present invention, a molded article excellent in water- and oil-repellency (particularly, alcohol-repellency) can be obtained. This molded article has a relative low cost and can be used for products such as home household articles (for example, a wash basin), stationeries (for example, an ink bottle), interior materials, sanitary supplies and medical supplies.
Modes for Carrying out the Invention
Examples of the thermoplastic resin (A) include a polyamide resin (for example, nylon 6, nylon 12, nylon 66, aromatic nylon), a polyester resin (for example, polyethylene terephthalate and polybutylene terephthalate), a polyolefin resin (for example, polyethylene, polypropylene, a copolymer of ethylene and propylene, a copolymer of ethylene or propylene and C4-C20 alpha-olefin, a terpolymer of ethylene, propylene and C4-C20 alpha-olefin, a copolymer of ethylene and vinyl acetate, a copolymer of propylene and vinyl acetate, a copolymer of styrene and alpha-olefin, polybutylene and polyisobutylene), a polyether resin, a polyetherester resin, a polyacrylate resin , an ethylenealkyl acrylate resin , a polydiene resin (for example, a polybutadiene and a copolymer of isobutylene and isoprene), a polyurethane resin, a polyetheretherketone resin, a polyetherimide resin, a polyethersulfone resin, polyphenylene sulfide resin, and a polycarbonate resin.
Among them, the polyolefin resin is preferable. Polyethylene, polypropylene, an ethylene/propylene random copolymer, an ethylene/alpha-olefin copolymer, a propylene alpha-olefin copolymer, and polybutylene can be used as the polyolefin resin.
Polyethylene includes high-density polyethylene and low-density polyethylene. Polypropylene includes isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, and amorphous polypropylene.
The above-mentioned isotactic polypropylene is high-crystallinity propylene based on isotactic propylene prepared by using a Ziegler-Natta catalyst or a metallocene catalyst. The above-mentioned isotactic polypropylene can be selected and available from generally commercially available propylene for the molding, such as propylene for injection molding, propylene for extrusion molding, propylene for film and propylene for fiber.
The above-mentioned amorphous polypropylene is propylene having extremely low crystallinity prepared by using a metallocene catalyst. The amorphous polypropylene may be a mixture of propylene having extremely low crystallinity prepared by using a metallocene catalyst (for example, in the amount of at least 50% by weight based on total amount of the mixture) and other propylene. The amorphous polypropylene is available as, for example, Tafthren T-3512 and T-3522 manufactured by Sumitomo Chemical Co., Ltd.
In the present invention, the thermoplastic resin (A) may be a mixture of at least two thermoplastic resins. As the thermoplastic resin (A), there may be used a resin mixture of a first resin with a second resin having a crystallinity or melting point lower than the first resin. One of the crystallinity and the melting point of the second resin may be lower than those of the first resin, or both of the crystallinity and the melting point of the second resin may be lower than those of the first resin. The second resin may be a mixture of at least two.
A preferable combination of the first resin/second resin are polypropylene/polyethylene, polypropylene/polybutylene, polypropylene/polypropylene, polypropylene/propylene-alpha-olefin copolymer, and polypropylene/ethylene-alpha-olefin copolymer. Preferably, in the polypropylene/polypropylene combination, the first resin is isotactic propylene (crystalline propylene), and the second resin is amorphous propylene.
In the resin mixture of first resin and second resin, the amount of the second resin may be from 1 to 60% by weight, for example, from 2 to 40% by weight, particularly from 3 to 30% by weight, especially from 5 to 20% by weight.
The crystallinity means the heat of crystallization measured by DSC (Differential Scanning Calorimetry). The crystallinity is a heat of exothermic peak evolved when heated from 20° C. to 200° C. and then cooled to 20° C. The heat of crystallization of the second resin may be lower by at least 1 J/g, preferably at least 5 J/g, more preferably at least 10 J/g, for example, at least 15 J/g, particularly at least 20 J/g than the heat of crystallization of the first resin.
The melting point can be measured by DTA (Differential Thermal Analysis) . The melting point is an endothermic peak evolved when heated from room temperature (10° C. to 30° C.). The melting point of the second resin may be lower by at least 10° C., preferably at least 15° C., for example, at least 20° C., particularly at least 25° C. than the melting point of the first resin.
The degree of segregation at surface of a fluorine-containing compound can be analyzed by conducting a fluorine analysis of surface according to XPS (X-ray photoelectron spectroscopy). The degrees of segregation at surface of the fluorine-containing compound can be compared by values of fluorine concentration at surface obtained by this method.
The fluorine-containing polymer (B) is preferably a homopolymer of a fluorine-containing polymerizable compound, or a copolymer of a fluorine-containing polymerizable compound and copolymerizable compound (particularly, a fluorine-free polymerizable compound), which are prepared by conventionally known technologies.
The fluorine-containing polymerizable compound is a fluorine-containing acrylate ester of the formula:
wherein X is a hydrogen atom, a methyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a CFX1X2 group (in which X1 and X2 are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom or an iodine atom), a cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, or a substituted or unsubstituted phenyl group;
In the fluorine-containing acrylate ester, X is preferably a hydrogen atom or a methyl group.
In the formula (I), the Rf group is preferably a perfluoroalkyl or perfluoroalkenyl group. The carbon number of the fluoroalkyl or fluoroalkenyl group is from 1 to 6, for example, from 1 to 4.
Examples of the fluoroalkyl group include —CF3, —CF2CF3, —CF2CF2CF3, —CF(CF3)2, —CF2CF2CF2CF3, —CF2CF(CF3)2, —C(CF3)3, —(CF2)4CF3, —(CF2)2CF(CF3)2, —CF2C(CF3)3, —CF(CF3)CF2CF2CF3, —(CF2)5CF3, and —(CF2)3CF(CF3)2.
Examples of the fluoroalkenyl group include —CF═CF2, —CF2CF═CF2, —(CF2 )2CF═CF2, —CF2C(CF3)═CF2, —CF(CF3 )CF═CF2, —(CF2 )3 CF═CF2, —C (CF3)2CF═CF2, —(CF2)2C (CF3)═CF2, —(CF2)4CF═CF2, —(CF2)4CF═CF2 and —(CF2)3C(CF3)═CF2.
Y is an aliphatic group having 1 to 10 carbon atoms, an aromatic or cycloaliphatic group having 6 to 10 carbon atoms, a —CH2CH2N(R1)SO2— group (in which R1 is an alkyl group having 1 to 4 carbon atoms) or a —CH2CH(OY1)CH2— group (in which Y1 is a hydrogen atom or an acetyl group). The aliphatic group is preferably an alkylene group (having particularly 1 to 4, for example, 1 or 2 carbon atoms) The aromatic or cycloaliphatic group may be substituted or unsubstituted.
Examples of the fluorine-containing polymerizable compound include acrylate esters of the formulas:
wherein Rf is a perfluoroalkyl group having 1 to 6 carbon atoms,
Specific examples of the fluorine-containing polymerizable compound include:
The copolymerizable compound may be a fluorine-free polymerizable compound.
The fluorine-containing polymer may contain a chlorine-containing polymerizable compound as repeating units. The chlorine-containing polymerizable compound is a compound having both a chlorine atom and a carbon-carbon double bond. Examples of the chlorine-containing polymerizable compound are vinyl chloride, vinylidene chloride, alpha-chloroacrylate (for example, an alkyl (having 1 to 30 carbon atoms) ester) and 3-chloro-2-hydroxypropyl methacrylate.
The fluorine-free polymerizable compound may be, for example, a fluorine-free alkyl (meth)acrylate.
The fluorine-free alkyl (meth)acrylate is generally a compound of the formula:
X1—CX2═CH2 (i)
wherein X1 is an alkyl carboxylate group (the alkyl group has 1 to 18 carbon atoms), and
The other copolymerizable compound may be various. Examples of the other copolymerizable compound include:
In the fluorine-containing polymer which is the copolymer, the amount of the fluorine-containing polymerizable compound may be at least 10% by weight, for example, from 20 to 80% by weight, particularly from 30 to 60% by weight. In the fluorine-containing polymer, the amount of the chlorine-containing polymerizable compound is at most 50% by weight, for example, from 0 to 30% by weight, particularly from 0.5 to 25% by weight.
The molecular weight of the fluorine-containing polymer may be generally from 1,000 to 1,000,000, particularly from 3,000 to 50,000 (for example, in terms of polystyrene measured by GPC).
The amount of the fluorine-containing polymer (B) may be from 0.1 to 10 parts by weight, for example, from 0.1 to 5 parts by weight, particularly from 0.5 to 3 parts by weight, based on 100 parts by weight of the thermoplastic resin (A).
The resin composition may contain additives (that is, auxiliaries), for example, a dye, a pigment, an antistatic agent, an antioxidant, a photo-stabilizers, a UV-absorber, a neutralizer, a nucleating agent, an epoxy-stabilizer, a sliding agent, a fungus preventing agent, a flame retardant, and a plasticizer, depending on the necessity.
The resin composition of the present invention can be obtained by kneading (for example, melt-kneading) the thermoplastic resin (A) with the fluorine-containing polymer (B). Generally, the thermoplastic resin (A) and the fluorine-containing polymer (B) are compatible under the melt state. The kneading can be conducted by conventional procedures, for example, a single screw extruder, a twin screw extruder and a roll. Thus obtained resin composition can be molded by conventional procedures such as an extrusion molding process, an injection molding process, a compression molding process and a film formation by press. The resin composition may be molded into various molded articles such as a fiber, a film and a tube. The obtained molded article may be heat-treated in an oven, a drying oven and the like, after the molding. The fiber may have a diameter of 0.2 to 2000 micrometers, for example, 0.5 to 50 micrometers, and a length of 0.2 mm to 200 mm, for example, 2 to 30 mm.
The resin composition of the present invention may be made in the form of a non-woven fabric. The non-woven fabric can be obtained by a carding method, an air laid method, a paper manufacturing method, or a melt blown method or a spun bond method wherein the non-woven fabric is directly obtained from the melt extrusion. In the melt extrusion, it is preferable to use a temperature of melting both the thermoplastic resin (A) and the fluorine-containing polymer (B). The basis weight of the non-woven fabric is not particularly limited, but may be from 0.1 to 1000 g/m2. The basis weight of the non-woven fabric is, for example, from 5 to 60 g/m2 for a surface material of a liquid-absorbing article and the like; from 10 to 500 g/m2 for an absorbing article, a wiper and the like; from 8 to 1000 g/m2 for a filter, according to uses of the non-woven fabric.
Hereinafter, the present invention will be illustrated in detail by the following Examples, which do not limit the present invention.
PP-3155 (manufactured by Exxon Mobil Corporation) (first resin) (isotactic polypropylene) (90 parts by weight), Polyethylene J1019 (manufactured by Ube Industries, Ltd.) (second resin) (low density polyethylene) (10 parts by weight), a copolymer (fluorine-containing polymer) (1 part by weight) between CnF2n+1CH2CH2OCOCH═CH2 (a mixture of compounds wherein n is 6,8,10,12 and 14 (n is 8 on average)) (fluorine-containing monomer, hereinafter referred to as “FA”) and stearyl acrylate (hereinafter referred to as “StA”), having a proportion of FA/StA═40/60 (weight ratio) were mixed at 180° C. in a twin screw extruder, and then molded by heat press to give a film.
The contact angle of a mixture liquid of IPA/water (70/30 (volume ratio)) and the contact angle of water were measured in order to evaluate the alcohol-repellency of this film. The segregation degree of the fluorine-containing compound at surface was measured by analyzing the fluorine component at surface by ESCA-3400 manufactured by Shimadzu Corporation. The melting point of the resin was measured by RTG220 manufactured by SII NanoTechnology Inc. The heat of crystallization of the resin was measured by DSC 822e manufactured by METTLER-TOLEDO K. K.
The same procedure as in Comparative Example 1 was repeated to prepare and evaluate a film, except using Polybutylene DP-8911 (manufactured by Shell Corporation) (10 parts by weight) as the second resin, and a copolymer of C6F13CH2CH2OCOCH═CH2 (fluorine-containing monomer, hereinafter referred to as “13FA”) and StA having a proportion of 13FA/StA═40/60 (weight ratio) as the fluorine-containing polymer.
The same procedure as in Example 1 was repeated to prepare and evaluate a film, except using a copolymer of C6F13CH2CH2OCOC (CH3)═CH2 (fluorine-containing monomer, hereinafter referred to as “13FMA”) and StA having a proportion of 13FMA/StA═40/60 (weight ratio) as the fluorine-containing polymer.
The same procedure as in Comparative Example 1 was repeated to prepare and evaluate a film, except using Polyethylene J5019 (manufactured by Ube Industries, Ltd.) (low density polyethylene) (10 parts by weight) as the second resin, and a copolymer (1 part by weight) of C4F9CH2CH2OCOCH═CH2 (fluorine-containing monomer, hereinafter referred to as “9FA”) and StA having a proportion of 9FA/StA═40/60 (weight ratio) as the fluorine-containing polymer.
The same procedure as in Comparative Example 1 was repeated to prepare and evaluate a film, except using a copolymer (1 part by weight) of C4F9CH2CH2OCO(CH3)═CH2 (fluorine-containing monomer, hereinafter referred to as “9FMA”) and StA having a proportion of 9FMA/StA═40/60 (weight ratio) as the fluorine-containing polymer.
The same procedure as in Comparative Example 1 was repeated to prepare and evaluate a film, except using a copolymer (1 part by weight) of C4F9CH2CH2OCOCCl═CH2 (fluorine-containing monomer, hereinafter referred to as “9FClA”) and StA having a proportion of 9FClA/StA═40/60 (weight ratio) as the fluorine-containing polymer.
The same procedure as in Example 3 was repeated to prepare and evaluate a film, except using only Polyethylene J1019 (manufactured by Ube Industries, Ltd.) (100 parts by weight) as the thermoplastic resin.
The same procedure as in Comparative Example 1 was repeated to prepare and evaluate a film, except using Tafthren T-3512 (manufactured by Sumitomo Chemical Co., Ltd.) (amorphous polypropylene) (10 parts by weight) as the second resin, and a copolymer (1 part by weight) of C4F9CH2CH2OCOCH═CH2 (fluorine-containing monomer, hereinafter referred to as “9FA”) and stearyl methacrylate (hereinafter referred to as “StMA”) having a proportion of 9FA/StMA═40/60 (weight ratio) as the fluorine-containing polymer.
Ingredients of Examples and Comparative Example are shown in Table 1, and contact angles and analysis results are shown in Table 2.
PP: polypropylene
PE: polyethylene
PB: polybutylene
From the results of Table 2, it is understood that the properties when the carbon number of the Rf group in the fluorine-containing polymerizable compound is 4 (Examples 3 to 7) and 6 (Examples 1 to 2) are at least comparable as the properties when the carbon number is 8 (Comparative Example 1).
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-187850 | Jun 2004 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP05/11503 | 6/23/2005 | WO | 1/8/2007 |
